R/sits_sf.R

In e-sensing/sits: Satellite Image Time Series Analysis for Earth Observation Data Cubes

#' @title Return a sits_tibble or raster_cube as an sf object.
#' @name sits_as_sf
#' @author Felipe Carvalho, \email{felipe.carvalho@@inpe.br}
#' @author Alber Sanchez, \email{alber.ipia@@inpe.br}
#'
#' @description Return a sits_tibble or raster_cube as an sf object.
#'
#' @param data   A sits tibble or sits cube.
#' @param as_crs Output coordinate reference system.
#' @param ...    Additional parameters.
#' @param crs    Input coordinate reference system.
#' @return       An sf object of point or polygon geometry.
#' @examples
#' if (sits_run_examples()) {
#'     # convert sits tibble to an sf object (point)
#'     sf_object <- sits_as_sf(cerrado_2classes)
#'
#'     # convert sits cube to an sf object (polygon)
#'     data_dir <- system.file("extdata/raster/mod13q1", package = "sits")
#'     cube <- sits_cube(
#'         source = "BDC",
#'         collection = "MOD13Q1-6",
#'         data_dir = data_dir
#'     )
#'     sf_object <- sits_as_sf(cube)
#' }
#' @export
sits_as_sf <- function(data, ..., as_crs = NULL) {
    UseMethod("sits_as_sf", data)
}

#' @export
#' @rdname sits_as_sf
sits_as_sf.sits <- function(data, ..., crs = "EPSG:4326", as_crs = NULL) {
    # Pre-conditions
    data <- .check_samples(data)
    # Convert samples to sf
    geom <- .point_as_sf(.point(data, crs = crs), as_crs = as_crs)
    # Bind columns
    data <- dplyr::bind_cols(geom, .discard(data, "time_series"))
    return(data)
}

#' @export
#' @rdname sits_as_sf
sits_as_sf.raster_cube <- function(data, ..., as_crs = NULL) {
    # Pre-conditions
    .check_is_raster_cube(data)
    # Convert cube bbox to sf
    data_sf <- .cube_as_sf(data, as_crs = as_crs)
    # Bind columns
    data <- dplyr::bind_cols(data_sf, .discard(data, "file_info"))
    return(data)
}